"Great. Can I go now?"
Moments later the TARDIS dematerialised and left a small gale in it's wake.
Samantha got on with her life. Time went by, she got old. She never married. She got her pension.
Then one day a Vvworp Vvworp sound could be heard. The Doctor had returned. "Would you like to change anything about your life?"
"I'd like more money."
"Ok one moment."
The TARDIS disappeared and reappeared almost as quickly. "Here you go"
The Doctor handed Samantha a lottery ticket. "These are the winning numbers for todays lottery. You'll be a millionaire."
"Great", she said.
"Would you like to come with me this time?" said the Doctor.
Then the TARDIS disappeared again.
Months went by. Samantha moved into a large house, she went on a cruise, and spent lots of money on gifts for herself. Then one day, the Doctor returned.
"I have a gift for you." he said.
"Oh? What is it?"
The Doctor moved aside to reveal a girl. "Meet Caroline." Caroline stood there looking a little uncomfortable.
"Why are you giving me a girl?"
"I think you need a challenge"
"But I'm happy as I am."
"But Caroline isn't. She hasn't got anyone. And she's not safe with me, I live a dangerous life. You can give her a good life."
"No, I don't want to."
Caroline looked at her sadly. "Look I'm sorry but I have enough on my plate living my own life."
"You need someone to care about. Ok let's put it this way, Caroline can stay here for two months. After that time I'll return."
Samantha looked in to the little girl's sad eyes, and sighed. "Ok Doctor, you've helped me a lot, I can do this for two months. If things aren't working out I'll sort something else out."
"Great! Ok that's sorted! Have fun Caroline, Samantha! I'll see you in two months!"
And with that the Doctor disappeared leaving the young girl and old lady in uncomfortable silence.